The present invention relates to power converters and, more specifically, to direct current to direct current step-down voltage converters (buck converters), and to direct current to direct current step-up voltage converters (boost converters).
Direct-current to direct current voltage converters (DCxe2x80x94DC converters) are used frequently in electrical and electronic systems to convert one voltage potential to another voltage potential. Such DCxe2x80x94DC converters typically have some form of regulation that controls an output voltage for the DCxe2x80x94DC converter as the electrical power consumed by an electrical load connected with the DCxe2x80x94DC converter changes. Such loads may include microprocessors, wireless communication devices, or any other electronic system or component that uses a DC voltage. One common type of DCxe2x80x94DC converter may be referred to as a buck converter. Buck converters step down an input voltage to provide a lower voltage potential output voltage. Another common type of DCxe2x80x94DC converter may be referred to as a boost converter. Boost converters step up an input voltage to provide a higher voltage potential output voltage.
One challenge that is faced when designing DCxe2x80x94DC converters, such as buck and boost converters, is the efficiency of such converters. Efficiency may be measured by the ratio of output power to input power. Therefore, efficiency for a given DCxe2x80x94DC converter indicates the amount of power consumed, or lost, as a result of the conversion from the input voltage potential to the output voltage potential. Current approaches for implementing DCxe2x80x94DC buck converters may have efficiencies on the order of 50% percent. As electrical and electronic systems continue to increase in complexity, such power losses due to voltage conversion may present more significant design challenges. Therefore, alternative approaches for buck converters may be desirable.
A direct current to direct current boost or buck voltage converter in accordance with the invention includes a plurality of switching devices that effect voltage conversion and control current flow direction in the converter. The converter also includes a control circuit for comparing an output voltage of the converter with a reference voltage, where the control circuit produces a comparison signal based on that comparison. A resonant gate-drive circuit, also included in the converter and coupled with the control circuit and the plurality of switching devices, opens and closes the plurality of switches in response to the comparison signal to effect voltage conversion and control current flow direction.